The DC/DC converter steps the high-voltage battery down to the 12 V system and replaces the alternator in hybrids and EVs. Its power stage carries temperature sensors so the controller can derate before the semiconductors overheat. P0C38 is the general circuit code for sensor A. Hyundai documents it on the 2027 Palisade Hybrid as P0C381C (failure type 1C, voltage out of range): the hybrid warning light comes on after the car has been parked for a long time, and bulletin 26-01-071H and campaign 9D8 cure it with an HPCU software update that improves the detection logic, so the sensor itself is usually fine. CARB requires the converter's inputs to be monitored as comprehensive components. Low, high and erratic signals have their own codes P0C3A to P0C3C.
High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
Symptoms
- Hybrid system warning light
- 12 V charging reduced or switched off
- Code appearing after the car has stood for a long time
Most likely causes
- Control unit software misjudging the sensor after long parking (Hyundai Palisade Hybrid)
- Fault in the circuit of sensor A inside the converter or power control unit
- Internal fault of the DC/DC converter requiring replacement
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0C38 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- C: Subsystem depends on the code range
- 38: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0C38?
If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
What causes code P0C38?
The most common causes are: control unit software misjudging the sensor after long parking (Hyundai Palisade Hybrid); fault in the circuit of sensor A inside the converter or power control unit; internal fault of the DC/DC converter requiring replacement.
Related codes
- P0C39DC/DC Converter Temperature Sensor A Range/Performance
- P0C3ADC/DC Converter Temperature Sensor A Low
- P0C3BDC/DC Converter Temperature Sensor A High
- P0C3CDC/DC Converter Temperature Sensor A Intermittent/Erratic
- P0C3DDC/DC Converter Temperature Sensor B Circuit
- P0D32DC/DC Converter A Over Temperature
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.